The present invention is in the field of heat exchangers, and more particularly in the field of evaporative, porous metal heat exchangers.
Conventional evaporative heat exchangers are generally of tubular construction and include discrete expansion valves. The coolant is typically contained in a separate stand-by reservoir and requires an active means to pump the coolant to the expansion valves. With this construction, such heat exchangers are characterized generally by relatively poor thermal "footprints", i.e. they do not provide a substantially uniform temperature outer surface. Furthermore, such heat exchangers require separate stand-by coolant reservoirs and an active means for pumping coolant to the expansion valves.
More recently, the heat exchangers have been developed where a coolant fluid is passed at relatively low flow velocity through a relatively large contact surface area, small fluid passages. Generally, the heat exchange matrix is in the form of a fine metal screen, or sintered metal powder, for example. These structures provide a desired porosity matrix which is characterized by a relatively high thermal conductivity. The resultant structures provide a relatively low flow impedance. However, these heat exchangers too are characterized by relatively poor thermal footprints.
It is an object of the present invention to provide an improved evaporative, porous metal heat exchanger.